Lubricating means for sewing machine loopers



Sept. 1, 1964 E. SCHENKENGEL 3,146,745

LUBRICATING MEANS FOR SEWING MACHINE LOOPERS Filed Dec. 21, 1961 I 8 I 1| I I mumunn I F 1 we? I Z? ,8 l0

3 lFi-- 32 l5 l3 3/ 30 WWW/01F: Emerich SI/IENKt'NGfL United States Patent 3,146,745 LUBRICATING MEANS FOR SEWING MACHINE LOOPERS Emerich Schenlrengel, Kaiserslantern, Pfalz, Germany, assignor to G. M. Pfaif A.G., Km serslantern, Pfaiz, Germany Filed Dec. 21, 1961, Ser. No. 161,080 Claims priority, application Germany Jan. 3, 1961 3 Claims. (Cl. 112256) The invention relates to sewing machines and more particularly to lubricating means for the loopers of sewing machines.

In known lubricating means for loopers oil is conducted from a supply container by way of a conduit to an oil chamber that is open in the rear and fastened to the hub of the looper and thence by way of a supply tube to the looper track. Lubricating means of this type cannot be conveniently regulated and above all they have the shortcoming that the flow of oil cannot be interrupted when the machine is at a standstill.

Lubricating means for loopers are also known where an oil chamber is removably mounted upon the hub of thp looper. Such a chamber is of closed construction and is capable to receive merely a small quantity of oil. This is delivered to the looper track in a relatively short period of time so that the chamber must be filled manually at relatively short intervals of time.

It is an object of the invention to provide a lubricating means for loopers which is simple and can be subsequently installed in existing machines with relative ease and which permits finely regulated control of the oil flow in close proximity to the looper track and which during slow sewing as well as standstill of the machine prevents flooding of the looper track. In addition the lubricating means for the looper are to be used for a looper unit which is provided for sewing machines having a lubricating means as well as also for normal slower operating machines which do not have any lubricating means. Furthermore, it is an object of the invention to meet the requirement of avoiding that the looper is subjected to any essential change of its existing construction which could adversely affect the efi'iciency of its technical function.

Accordingly, the invention achieves these objects with a lubricating means for the loopers of sewing machines where the oil is conducted through a conduit from an oil chamber that is open at the rear and secured to the hub of the looper and thence by way of a supply duct to the looper track to provide in the bottom of the looper an opening into which the supply tube extends which is connected with the removable oil chamber, furthermore to threadedly connect with the supply tube a regulating screw, the head of which is completely disposed within the opening and finally to provide the conduit in such an arrangement with a wick which connects the supply container or reservoir with the oil chamber so that the wick is in engagement with the wall of the oil chamber.

By providing a felt ring in the oil chamber which has suction qualities there is maintained proximate the looper track a reserve of oil which has a butler effect that adapts itself to the varying demand for oil.

It has been found to be particularly advantageous to form the aperture in the bottom or rear wall of the looper conically and to have its surface which meets the lateral wall merge into an oil groove in the side wall of the looper so that the oil which has been cast off from the end of the supply tube by centrifugal force is safely conducted into the interior of the looper.

Further objects and advantages of the invention and details thereof which result in the foregoing advantages will become apparent from the following specification of 3,146,745 Patented Sept. 1, 1964 an embodiment illustrated in the accompanying drawings in which:

FIG. 1 is a perspective illustration from the bottom of a sewing machine provided with the new lubricating means for loopers;

FIG. 2 is a front view of the looper lubricating means with the base plate partly cut away;

FIG. 3 is a section through the looper and through the oil chamber, and

FIG. 4 is a section taken along line IV-IV in FIG. 3.

The looper 1 is secured by means of its hub 2 on the looper shaft 3 by means of a screw 4 and is driven by the looper drive shaft 5 (FIG. 1) by means of a pinion gear (not shown) inside the transmission box 6. The bobbin housing '7 which is stationary during sewing operations is journalled in the looper track 8 (FIG. 3) in the wall 9 of looper 1.

For lubricating the looper track 8 an oil chamber 10 is removably secured by means of screws 11 upon the hub 2 of the looper 1. The oil chamber comprises a wall 12 in the form of a disk, a cylindrical wall 13 which encompasses the looper shaft 3 and a mantle 14 which is frusto-conical in shape where the largest diameter of the cone is connected with the circumference of wall 12 so that the removable chamber 10 is open on its side which is remote from the looper and thus forms a hollow annular space 15. The wall 12 has a bore 16 adjacent the upper outer circumference of the hollow annular space 15 which is disposed opposite a conical opening 17 in the bottom or rear wall 18 of the looper 1. A supply duct in the form of a tube 19 secured in the bore 16 (FIG. 4) extends parallel to said shaft and projects with its free end into the aperture 17. The supply duct or tube 19 is provided within its free end with a thread for receiving a control screw 20 having a head 21 which can be more or less approached to the pointed wedgeshaped wall 22 of the supply tube 19. In this manner exact control of the quantity of oil in the proximity of the looper track is accomplished.

The oil which, owing to centrifugal force, flows out during rotation of the looper between the head 21 of the control screw 20 and the wall 22 is conducted through the conically shaped aperture 17 into an oil groove 23 provided in the wall 9 of the looper, which connects the aperture 17 with the looper track 8. A spring 24 which at the one end engages the screw 2% and at the other end rests against a bottom 26 that terminates the supply tube and which is provided with a passage 25, serves for securing the screw 29 against inadvertent rotation.

A felt ring 27 is disposed in the hollow space 15 of the lubricant chamber 10. This ring can store a certain quantity of oil and supply it in suitable doses to the looper track.

Feeding lubricant to the felt ring 27 is effected from a supply container or reservoir 29 which is mounted by means of screws 28 (FIGS. 1 and 2) below the base plate of the sewing machine. A conduit 30 which leads from the supply container slidingly receives one end of a tube 31, the other end of which projects into the hollow space 15 of the lubricant chamber 10. The conduit 30 is provided on the supply container or reservoir 29 in such a manner that it extends into the wall of the container in normal position of the machine as well as also in tilted condition above the highest possible filling level.

The oil is conducted through a wick 32 (FIG. 3) disposed in conduits 30 and 31 which at one end extends into the supply container 29 and at the other end engages the wall 12 of the chamber 10. However, in this manner only such an amount of oil is supplied by suction as the rotating wall 12 will sweep from the end of the oil wick 32 by which it is engaged. This results in that during standstill of the sewing machine no oil supply is fed 9 LB from the container 29 into the lubricant chamber 10 while when the machine is running only so much is supplied as the saturation amount of the felt ring 27 which serves as the buffer will permit.

The supply container 29 has a filler stub 34 which can be closed by means of a sealing screw 33 which in tilted condition of the machine serves for filling the container while an oil viewing glass 35 permits determination of the oil level. An aperture 36 which permits the escape of air at the same time insures against exceeding the level of oil in the container.

Having now described my invention with reference to the embodiment illustrated in the drawings, I do not wish to be limited thereto, but what I desire to protect by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. Lubricating means for the looper of a sewing machine of the type where oil is fed from a container by way of a conduit to an oil chamber secured to the hub of the looper and from there to the looper track through a supply duct, said machine having a base and said means comprising a looper having a hub mounted on a looper shaft on the base of the machine and having a rear wall defining an aperture, an oil chamber having an inner disk shaped wall and an outwardly extending frusto-conical wall defining an annular open space around said shaft and having a cylindrical portion slidingly received on and removably secured to said hub, a supply duct extending parallel to said shaft from said oil chamber through said disk shaped wall into said'aperture, a regulating screw threadedly received in said supply duct and having a head disposed completely in said aperture, an oil reservoir mounted on said base, a conduit between said reservoir and said oil chamber and a wick in said conduit, said Wick having one end extending against said inner wall of said oil chamber.

2. Lubricating means for the looper of a sewing machine of the type where oil is fed from a container by way of a conduit to an oil chamber secured to the hub of the looper and from there to the looper track through a supply duct, said machine having a base and said means comprising a looper having a hub mounted on a looper shaft on the base of the machine and having a rear wall defining an aperture, an oil chamber having an inner disk shaped wall and an outwardly extending frusto-conical wall defining an annular open space around said shaft, and having a cylindrical portion slidingly received on and removably secured to said hub, a supply duct extending parallel to said shaft from said oil chamber through said disk shaped wall into said aperture, a regulating screw threadedly received in said supply duct and having a head disposed completely in said aperture, an oil reservoir mounted on said base, a conduit between said reservoir and said oil chamber, a wick in said conduit, and a felt ring disposed on said inner wall, said wick having one end in lubricating relationship with said felt ring.

3. Lubricating means for the looper of a sewing machine of the type where oil is fed from a container by way of a conduit to an oil chamber secured to the hub of the looper and from there to the looper track through a supply duct, said machine having a base and said means comprising a looper having a hub mounted on a looper shaft on the base of the machine and having a rear wall defining an aperture, an oil chamber having an inner disk shaped wall and an outwardly extending frusto-conical wall defining an annular open space around said shaft and having a cylindrical portion slidingly receeived on and removably secured to said hub, a supply duct extending parallel to said shaft from said oil chamber through said disk shaped wall into said aperture, a regulating screw threadedly received in said supply duct and having a head disposed completely in said aperture, an oil reservoir mounted on said base, a conduit between said reservoir and said oil chamber, a wick in said conduit, and a felt ring disposed on said inner wall, said wick having one end in lubricating relationship with said felt ring, said aperture having a conical conformation and said looper having a looper track and a lubricating groove extending from a wall of said conical aperture to said track.

References Cite-d in the file of this patent UNITED STATES PATENTS 875,618 Parkes Dec. 31, 1907 2,334,644 Parry Nov. 16, 1943 2,346,139 Myers Apr. 11, 1944 2,659,331 Mousset Nov. 17, 1953 2,764,113 Schaefer Sept. 25, 1956 2,848,967 Nicolay Aug. 26, 1958 3,060,877 Ketterer Oct. 30, 1962 

1. LUBRICATING MEANS FOR THE LOOPER OF A SEWING MACHINE OF THE TYPE WHERE OIL IS FED FROM A CONTAINER BY WAY OF A CONDUIT TO AN OIL CHAMBER SECURED TO THE HUB OF THE LOOPER AND FROM THERE TO THE LOOPER TRACK THROUGH A SUPPLY DUCT, SAID MACHINE HAVING A BASE AND SAID MEANS COMPRISING A LOOPER HAVING A HUB MOUNTED ON A LOOPER SHAFT ON THE BASE OF THE MACHINE AND HAVING A REAR WALL DEFINING AN APERTURE, AN OIL CHAMBER HAVING AN INNER DISK SHAPED WALL AND AN OUTWARDLY EXTENDING FRUSTO-CONICAL WALL DEFINING AN ANNULAR OPEN SPACE AROUND SAID SHAFT AND HAVING A CYLINDRICAL PORTION SLIDINGLY RECEIVED ON AND REMOVABLY SECURED TO SAID HUB, A SUPPLY DUCT EXTENDING PARALLEL TO SAID SHAFT FROM SAID OIL CHAMBER THROUGH SAID DISK SHAPED WALL INTO SAID APERTURE, A REGULATING SCREW THREADEDLY RECEIVED IN SAID SUPPLY DUCT AND HAVING A HEAD DISPOSED COMPLETELY IN SAID APERTURE, AN OIL RESERVOIR MOUNTED ON SAID BASE, A CONDUIT BETWEEN SAID RESERVOIR AND SAID OIL CHAMBER AND A WICK IN SAID CONDUIT, SAID WICK HAVING ONE END EXTENDING AGAINST SAID INNER WALL OF SAID OIL CHAMBER. 